Disposal of surplus ordnance represents a significant problem for the Department of Defense. As new weapon systems are developed and enter service, these systems are acquired in mass quantities to comply with combat readiness requirements. Obsolete ordnance must then be disposed of by various means, including use in training, use in conflict, and destruction. Regardless of disposal method, the explosive components in ordnance must be rendered completely inert and no longer an explosive. The most common method to dispose of surplus ordnance by destruction is open-burn, open-detonation (OBOD). Ordnance to be disposed by OBOD is placed in a shallow pit and burned or detonated. While effective at large-scale and cost-effective disposal, OBOD may not be compliant with environmental regulations. Further, environmental regulations are changing such that OBOD will not be permissible in the future.
Recognizing the limitations of OBOD due to environmental compliance requirements, prototype incineration facilities have been designed and built to burn ordnance in a contained system, thereby preventing the release of pollutants into the environment. These facilities are equipped with filters and scrubbers that clean the gases emitted by the combustion process and remove any contaminants. Although this process is effective from an environmental compliance perspective, it is not practical due to complexity and cost compared to OBOD. In particular, such facilities treat ordnance articles one-at-a-time, a disposal rate that is far too small against the need to dispose of many thousands of articles.
The problem of disposal and passivating ordnance extends beyond surplus ordnance to other types of ordnance such as mines, which include sea-mines and landmines. Landmines maim or kill countless civilians every year in areas that were sown with landmines during previous or ongoing conflicts. Thousands of square miles of arable land are affected, contributing to the ongoing poverty of people in these areas, and to the nurturing environment for terror groups.
A modern landmine is notoriously difficult to detect and dispose of due to the parts being made mostly of plastic. This also makes them resistant to environmental degradation. They can persist as an operable device for many decades. While deployed on a much smaller scale than landmines, sea-mines are similarly difficult to detect and have long operable lives. A great deal of research and development effort has been, and continues to be, expended on developing ways to detect and dispose of mines.
There has been at least one attempt to use microorganisms to biopassivate the energetic material in explosive ordnance. It involved incorporating a bioreactor into the artillery shell or landmine at the time of manufacture. In the case of the artillery shell, the bioreactor is activated when the shell is fired. If the shell fails to explode, then the microorganisms in the bioreactor are released to passivate the energetic material. In the case of the land mine, the bioreactor is activated after a given amount of time to passivate the energetic material and render the landmine harmless.
This attempt at biopassivation of explosive ordnance suffered from a number of problems. One problem is that it was limited to fired, but unexploded artillery shells and landmines and only to situations where the bioreactor is incorporated into these munitions at the time of manufacture. It offered no solution to the disposal of surplus ordnance. It offered no solution to the problem of passivating surplus unfired ordnance manufactured without an integral bioreactor. Another problem is that it failed to account for toxic materials in the energetic material such as heavy metals that prevent or inhibit the growth of the microorganisms.
Yet another problem associated mainly with the artillery shell concept is that the bioreactor and the microorganisms inside it are subjected to extreme forces during the firing sequence of the artillery shell. These forces are likely to frequently damage or potentially even destroy the microorganisms and render the bioreactor ineffective.